Abstract: Bioadhesives coatings increase the gastrointestinal retention time of orally-ingested medicaments. Certain bioadhesive coatings producing a fracture strength of at least 100 N/m2, as measured on rat intestine, when applied to at least one surface of a pharmaceutical dosage form for oral delivery of a drug, result in a gastrointestinal retention time of at least 4 hours in a fed beagle dog model, during which the drug is released from the dosage form. Multi-layer tablets, particularly those including hydrophobic excipients, are useful in administering hygroscopic and/or deliquescent drugs. In addition, varying the amount of drug in multi-layer tablets allows the release rate of the drug to be controlled.

Abstract: Polymers with improved bioadhesive properties and methods for improving bioadhesion of polymers have been developed. A compound containing an aromatic group which contains one or more hydroxyl groups is grafted onto a polymer or coupled to individual monomers. In one embodiment, the polymer is a biodegradable polymer. In another embodiment, the monomers may be polymerized to form any type of polymer, including biodegradable and non-biodegradable polymers. In some embodiments, the polymer is a hydrophobic polymer. In the preferred embodiment, the aromatic compound is catechol or a derivative thereof and the polymer contains reactive functional groups. In the most preferred embodiment, the polymer is a polyanhydride and the aromatic compound is the catechol derivative, DOPA. These materials display bioadhesive properties superior to conventional bioadhesives used in therapeutic and diagnostic applications.